Datatypes R2 Issue 27

Introduction

EIVL<TS>: Deprecate many of the current event codes that are of the form Ax, Px, Ix (ante-x, post-x, inter-x), such as ACV, PCV, ICV. Instead put in codes for simply C, CM, CD, CV, etc. to indicate the event. Then the offset interval would be interpreted as follows: negative offsets are measured from the start of the event (e.g., 30 min before breakfast) and positive offsets are measured from the end of the event (e.g., 2 hours after meals.) The problem with the present definition is that the offset direction (whether it is before or after) is indicated by the sign AS WELL AS the event code.

And the EIVL component summary is wrong

? backward compatible: parts of this are not backward compatible

Discussion

Removal of Unrelated Ammedment

I (Gschadow 17:51, 7 June 2007 (CDT)) removed the following ammendment:

Also add the following event codes (with the offset semantics as specified in previous change)

* COIT Sexual intercourse

* DIAP Diaper change

* DEFEC Defecation

this is an issue separate from EIVL. The original proposal was vetted by Pharmacy SIG. This ammendment, however, was discussed and rejected by the same group back in 2004 and after heavy confusion it was unanimously determined that it should not be done. The consensus can be seen in some of the following statements from the email archive:

Lloyd McKenzie [Sep 9 2005 - 6:12pm]:

The EIVL datatype should be restricted to use for [...] setting where the specified timings can be resolved to specific times or time-windows based on [...] schedules. EIVL event types should be restricted to those which are resolvable [...]. All other events should be communicated as preconditions with offsets [pauseQty].

Gunther Schadow [Sep 9 2005 - 6:30pm]:

I agree to the intent. [...] I think it comes darn close to the original intent of EIVL, which was to spefify *regular* events that are usually relatively regularly timed, such as meal and sleeping, but not sex and other urges for relief.

Julie James [Sep 12 2005 - 5:44am ]:

I stick with my view that anything that can be "mathematically measured time" for a dosage is part of GTS; therefore if you say "one at breakfast" when you mean "one on the 8am drug round" then those are synonymous phrases - if you want to capture that synonymy in a part of [...] EIVL, then that's OK.

If a dosage timing is in any sense "circumstantial" and cannot be exactly predicted without using another variable other than the passage of time [...] is not catered for in GTS, which is "mathematical".

I am trying to follow the same logic for GTS that UCUM uses for measurement of quantity; if you can reproducibly measure the pattern of time for a dosage, use GTS, if you can't, don't.

My rationale is to try to move to sensible maths for dosage checking (we kill more people by wrong dosage than by anything else) and also to know when there is *not* maths for dose checking, so that applications can handle that too, rather than trying (as we have been for so many years) to make inferences that are all too often wrong.

Tom De Jong [10 September 2005 21:27]:

I think the difference is between 'regularly scheduled' and 'regularly occurring'. Meals and bedtime can be regularly scheduled, but things like menstruation and defecation are only regularly occurring. They aren't scheduled. I apologize for trying to squeeze these concepts into EIVL last year, because that would have stretched the concept too far (which resulted in the complete data type being suspended' by the Pharmacy SIG until now).

I hope that settles it. Gschadow 17:51, 7 June 2007 (CDT)

Disposition

Motion: Approve these changes

Approve: Grahame
Oppose:
Abstain:

Links

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Skype thread

Gunther. A question from INM about your proposed changes to the EIVL.event code list: [8:38:11 AM] Grahame Grieve says: if you take the code for "Before Breakfast" away (as you propose to do), then how do you specify "before breakfast" without being specific as to how many minutes before breakfast in the offset? [8:42:34 AM] Gunther Schadow says: Darn [8:42:59 AM] Gunther Schadow says: That proposal came from group discussion at Pharmacy SIG. [8:45:01 AM] Gunther Schadow says: It was so much simpler that way. Now we need a new Null Flavor for unknown negative number :) ... only half way kidding. [8:45:17 AM] Grahame Grieve says: actually the question came from Scott on behalf of Pharmacy [8:45:24 AM] Gunther Schadow says: Funny [8:45:39 AM] Grahame Grieve says: my initial response was, that's not an EIVL. that's a something else [8:45:42 AM] Gunther Schadow says: He was not on the phone then, I guess. [8:45:51 AM] Grahame Grieve says: which is kind of the same as your response from a different perspective [8:46:24 AM] Gunther Schadow says: Well, I'm afraid that it is an EIVL and it is one of those requirements that are real out there but when you really think about them they blow your mind. [8:47:29 AM] Grahame Grieve says: do we really want to allow such woolly thinking? as a consumer, I hate that "before breakfast" business. Can I take it the night before on the basis that that's before my breakfast? [8:47:59 AM] Grahame Grieve says: does it need to be half an hour, or only a few minutes? Why can't you just say? [8:48:10 AM] Grahame Grieve says: but I'm just a consumer here. I've never worked in pharmacy [8:53:32 AM] Gunther Schadow says: I completely agree with your woollly thinking complaint. It's silly. And yet, people are taking sillyness very seriously. I can already see someone throwing tomatoes at HL7 again for disregarding such important SAFETY ISSUE :) [8:54:11 AM] Grahame Grieve says: agree; in fact, I can see tomatoes being thrown for either allowing or disallowing it. hopefully they aren't rotten [8:54:45 AM] Gunther Schadow says: We should just press the matter. Why don't we reply that this request came from a group discussion in the pharmacy committee. I may even have details. [8:54:46 AM] Grahame Grieve says: Dennis says tomatoes are $7/kg here. You could do well out of it if you can catch them [8:55:15 AM] Grahame Grieve says: ok. goes to harmonisation like that. (We agreed, just with a note about the question from Scott) [8:55:21 AM] Gunther Schadow says: I know you guys down under will even welcome being squirted with water :) [8:55:43 AM] Grahame Grieve says: yes, water would be good, as long it's not from the supply [8:59:59 AM] Gunther Schadow says: Looking in my archives:

From: Gunther Schadow <gunther@aurora.regenstrief.org> To: Hallowell Robert <robert.hallowell@siemens.com> Date: Oct 06 2004 - 7:45pm

It may help to know that these PCM ACM etc. codes that are in EIVL were not originally part of the HL7 v2.x specification until such time (in 1998) when Japanese members had requested them. This means, you may not find many systems in the U.S. that casually link timing to meals, unless, as you say, it is really important, in which case it is not a casual link but additional instructions. [9:02:05 AM] Grahame Grieve says: with reference to http://informatics.mayo.edu/wiki/index.php/Datatypes_R2_Issue_27, I think that Julie's comments make sense, which is why such a woolly concept as "sometime before breakfast" isn't and EIVL [9:09:52 AM] Gunther Schadow says: Yes. Agreed. Now if Scott does not agree, then we should bring it up with Pharmacy SIG for review. These people are very reasonable. [9:11:03 AM] Grahame Grieve says: I think Scott would be reasonable. He was mainly asking how it should be done. Which is still open in my mind. If we say, you can't do this with EIVL, then how would you do it?